Electrically controlled, untethered soft robot built out of four soft tubular actuators, a microcontroller and battery. The robot can be programmed to walk or carry an object. Credit: David Baillot/UC San Diego Jacobs School of Engineering
Engineers at the University of California San Diego have developed a way to build soft robots that are compact, portable and multifunctional. The advance was made possible by creating soft, tubular actuators whose movements are electrically controlled, making them easy to integrate with small electronic components.The actuators are made from a type of material used for artificial muscles in robots, called liquid crystal elastomers. They are composed of liquid crystal molecules embedded in a stretchy polymer network. What's special about these materials is they change shape, move and contract in response to stimuli such as heat or electricity—similar to how muscles contract in response to signals from nerve cells.
To construct each actuator, engineers sandwiched three heating wires between two thin films of liquid crystal elastomer. The material is then rolled into a tube, pre-stretched and exposed to